Multiple pole switch for producing simultaneous opposite switching operations

ABSTRACT

A multiple pole electric switch of the type wherein different poles are respectively connected and disconnected by a single movement of the switch which includes a plurality of stationary contacts, a pluraLity of movable contacts preferably positioned to bridge a gap between a pair of the stationary contacts, and insulating projection means intermediate the pair of stationary contacts. Each movable contact includes a recess which engages the projection and an extending portion which engages one of the stationary contacts in the closed position. In the open position, the movable contact is moved so that the extending portion is lifted out of engagement with the stationary contact by the projection. At least one of the movable contacts is mounted for opposite movement relative to the remainder of the movable contacts so that the one contact opens when the remainder close and closes when the remainder open. Preferably, the extending portion of the movable contact is engaged by the projection and spaced from the stationary contact for a sufficient proportion of its movement so that, during switch operation in either direction, the initially closed contacts open before the initially opened contacts close.

United States Patent (72] Inventor William H. O'Connor. 111

Baltimore. Md. 1

[21] Appl. No. 839,447

(22] Filed July 7,1969

[45] Patented Aug. 10,1971

173] Assignee The Black and Decker Manufacturing Company Towson, Md.

[54] MULTIPLE POLE SWITCH FOR PRODUCING SIMULTANEOUS OPPOSITE SWITCHINGOPERATIONS 10 Claims, 8 Drawing Figs.

[52] U.S.Cl 200/16 R,

[51] int. Cl ..ll0lh 15/00 [50] Field of Search 200/6, 67.7,

16, 157, 166 A, 164,6R, 16R, 67 G, 164R [56] References Cited UNITEDSTATES PATENTS 3,030,459 4/1962 Elliott et al. 200/6 A 3,165,604 1/1965Sorenson ZOO/67.7

3,188,697 6/1965 Schink 200/16 3,222,488 12/1965 Matthewsm, 200/157X3,356,814 12/1967 France,.lr 200/157 3,415,966 12/1968 MatthewsABSTRACT: A multiple pole electric switch of the type wherein differentpoles are respectively connected and disconnected by a single movementof the switch which includes a plurality of stationary contacts, apluraLity of movable contacts preferably positioned to bridge a gapbetween a pair of the stationary contacts, and insulating projectionmeans intermediate the pair of stationary contacts. Each movable contactincludes a recess which engages the projection and an extending portionwhich engages one of the stationary contacts in the closed position. inthe open position, the movable contact is moved so that the extendingportion is lifted out of engagement with the stationary contact by theprojection. At least one of the movable contacts is mounted for oppositemovement relative to the remainder of the movable contacts so that theone contact opens when the remainder close and closes when the remainderopen. Preferably, the extending portion of the movable contact isengaged by the projection and spaced from the stationary contact for asufficient proportion of its movement so that, during switch operationin either direction, the initially closed contacts open before theinitially opened contacts close.

PATENTEU AUG 1 01971 SHEET 1 OF 2 FIG. 5

INVENTOR WILLIAM H. O'CONNOR III ATTORNEY MULTIPLE POLE SWITCH FORPRODUCING SIMULTANEOUS OPPOSITE SWITCHING OPERATIONS This inventionrelates to an improved electric switch wherein different circuits aresimultaneously connected and disconnected by a single movement of theswitch.

It is frequently desirable in electric switching to control multiplecircuits simultaneously or in an essentially simultaneous manner butwith a predetermined ordering of the circuit operation. A primaryexample of this is in switches for rotary electric motor-driven devices.Particularly in the case of electric saws, it is of the utmostimportance for safety purposes that the brake of the device begin tooperate immediately after the motor has been disconnected. Actuation ofthe brake before the motor has been disconnected can cause seriousdamage to the motor while delay of the braking action for too long aperiod of time after the motor has been disconnected may result incutting the work beyond the desired stopping point or, where operatorcarelessness may be involved, injury to the operator. It is also ofprimary importance in the fields of tools and, particularly, portabletools, that the manufacturing cost be minimized.

Accordingly, the present invention is directed to the provision of amultiple pole switch which provides the desired relationship ofoperations and which performs these operations in the course of a singlemovement.

An object of this invention is the provision of a new and improvedswitch which performs ordered operations on a multiplicity of circuitsin a single movement of the switch.

It is another object of this invention to provide a new and improvedswitch which provides an ordered connection and disconnection ofmultiple circuits in a single switch movement.

A further object of this invention is the provision of a new andimproved low cost switch for controlling multiple circuits.

Other objects and advantages of the present invention will be apparentfrom the accompanying drawings and description and the essentialfeatures thereof are set forth in the appended claims.

Briefly, in accord with one embodiment of this invention, I provide amultiple pole switch of the type wherein different poles arerespectively connected and disconnected by a single movement of theswitch. Specifically, the switch includes a plurality of stationarycontacts and a plurality of movable contacts, each of the movablecontacts being arranged to engage one of the stationary contacts uponappropriate movement. This is accomplished by providing the movablecontacts with an extending portion and a recessed portion and byproviding an insulating projection adjacent the stationary contacts sothat, when the recessed portion registers with the projection, theextending portion engages the stationary contact and when the movablecontact is moved, the projection cams the contacts apart by engaging theextending portion. In particular accord with this invention, the movablecontacts are arranged so that at least one of the movable contacts ismoved from the engaged position to the disengaged position by the samemovement of the switch-operating member which moves at least one othermovable contact from the disengaged position to the engaged position.

In a preferred embodiment of this invention, the extending portion ofthe movable contact is engaged by the projecting means and spaced fromthe stationary contact for a sufficient proportion of the distance movedso that the initially closed contacts are opened by engagement of theextending portion with the projection before the initially open contactsare allowed to close.

In The Drawings FIG. I is a perspective. exploded view of a switchconstructed in accord with the present invention;

FIGS. 2A and 2B are simultaneous views of the positions of two differentsets of contacts in one stable position of the operating lever of aswitch in accord with this invention;

FIGS. 3A and 3B are simultaneous views of the contacts of FIGS. 2A and28 at an intermediate point during the movement of the operating lever;

FIGS. 4A and 4B are simultaneous views of the contacts of FIGS. 2A and28 after movement of the operating lever to its second position; and

FIG. 5 is a schematic illustration of a circuit incorporating a switchin accord with the present invention.

Theswitch assembly shown in FIG. 1 includes a base 10 of insulatingmaterial which carries a pair of stationary contacts 11, 12. The reverseside of the insulating base 10 is substantially similar and it carriesanother pair of stationary contacts 13, 14 shown in FIG. 2B. A housing,not shown, is usually provided which encloses the sides of the switch.Contact is made to the stationary contacts by inserting the bared end ofa wire from the external circuit through the bottom of the base so thatthey are gripped in place against the stationary contacts ll, 12 by thespring metal members 25, 16. Further detail as to the construction anduse of this switch is contained in U.S. Pat. Nos. 3,222,488 and3,415,966, the subject matter of which is incorporated herein byreference.

The switch also includes a pair of movable contacts 17 and 18. Thesemovable contacts are mounted in an actuator block 19 which is providedwith slots 20 and 21. The slots are sized so that they do not permit anysubstantial movement in the horizontal direction but they do permitvertical movement of the contacts. The contacts are biased downwardlyagainst the stationary contacts by means of springs 22, 23 which aremounted in any appropriate manner such as by means of cylindrical holes,not shown, which extend within the actuator block above the slots 20 and21.

In the illustrated embodiment, the actuator 19 is operated to move themovable contacts by means of a pivoted rocker 24 having a finger 25which extends into a central aperture 26 in the actuator 19. The rocker24 is pivoted, for example by means of a pin, not shown, which extendsthrough an aperture 27 and is supported at each end by the externalhousing. The sides of the aperture 26 are preferably sloped toaccommodate angular entry of the finger 25 while the lower portion ofthe aperture 26 is relatively tightly fitted to the finger so that thearcuate motion of the finger is converted to linear motion of theactuator.

The motion of the movable contact 17 in response to movement of therocker 24 is shown in FIGS. 2A, 3A and 4A. FIG. 2A is a side elevationof the side shown in FIG. 1 with the contact 17 in the open position,which corresponds to depression of the left-hand side of the rocker 24so that the actuator 19 and contact 17 are moved to the right in FIG.2A. In this position, an extending portion 30 of the contact 171sengaged with the stationary contact 12 and a second extending portion 31is spaced from the stationary contact 11 due to the camming action of anintermediate projecting portion 32 of the insulating base againstsurface 34. FIG. 3A illustrates an intermediate point in the switchmotion and the position of contact 17 is illustrated at a moment duringthe depression of the right-hand side of rocker 24. As illustrated, thecontact 17 has begun to move to the left in FIG. 3A and the extendingportion 31 has moved relative to the projection 32. However, due to thelength of the extending portion 31 relative to the distance throughwhich contact 17 has been moved, the contact 17 has not yet engaged thestationary contact 11. In FIG. 4A, the movement of the contact 17 hasbeen completed, corresponding to complete depression of the right-handside of rocker 24. In this position, the extending portion 31 has movedaway from the projection 32 so that the projection now registers with arecess 33 in the contact 17 and the extending portion 31 is now inengagement with the stationary contact 11. Meanwhile. the extendingportion 30 has remained in sliding contact with the stationary contact12. Good electrical con tinuity between the movable contact 17 and thestationary contacts II and I2 is insured by the action of spring 23.

In accord with the present invention, the contact 18, illustrated inFIG. 2B, is closed when contact 17 is opened and is open when contact 17is closed. Also, in the preferred con- 1. A multiple pole electricswitch of the type wherein difstruction, there is a point in theswitching operation when both ferent poles are respectively connectedand disconnected by a contacts are open. To demonstrate this, FIGS. 2B3B and 48 single movement of the switch comprising:

illustrate the position of contact 18 at exactly the same moan insulatorbase;

ments in time as illustrated in FIGS. 2A, 3A and 4A respec- 5 aplurality of stationary electrical contacts mounted on said tively. InFIG. 2B, the contact 18 is in its right-hand position, base;

corresponding to depression of the left-hand side of rocker 24. aplurality of movable electrical contacts mounted for lon- Thus, theprojection means 42 is within the recess 43 and the gitudinal movementrelative to said base, each of said extending portions 40 and 41 arerespectively in contact with movable contacts having a portion arrangedto be moved the. stationary contacts 13 and 14 due to the action of thecoil into engagement with one of said stationary contacts; spring 22. InFIG. 3B, the contact 18 has been moved to the said movable contacts andsaid base having cooperating left the same distance as contact 17 inFIG. 3A. However, due camming surfaces;

to the immediate action of the projection 42 against an initial each ofsaid movable contacts being movable between a point of camming urface 44at th tt m f p rti 41, th l 5 first position wherein said cammingsurfaces permit said connection between extending portion 41 andstationary conengaging -tio t ta t aid stationary contact and a tact 14has been broken. Thus, as illustrated in FIGS. 3A and second positionwherein said camming surfaces separate 38, there is a moment during theoperation of the rocker 24 aid engaging ortion from said stationarycontact; and when both contacts 17 and 18 are disconnected from themeans f ovin at lea t one of said movable contacts respective stationarycontacts which complete the external 20 between id fi t d aid ond oitions during the circuit. This is the preferred embodiment of thisinvention; same i h operation as h movement f h remainder however, yShaping the contacts that the distance of said contacts between saidsecond and said first positraversed by the projection within the recessis larger than that i under the extending P the pp effect could be 2. Anelectric switch as claimed in claim 1 wherein said tained and a momentwould exist when both circuits would be camming surfaces incjude aprojection f i base, a closed Prior to opening ofthe initially closedcontactsrecessed portion in said movable contact, and an extending InFIG. 4B, depression of the right-hand side of rocker 24 portion f idmovable Contact;

has been completed so that the contact 18 is now moved Said engagingPortion comprises a part of said extending completely to the left. Theengagement of projection means portion;

42 with extending portion 41 is, of course, continued since the Saidmovable Contact being positioned so that said recessed movement ofContact 18 from F 38 G 48 Simply portion registers with said projectionin said first position; causes the surface 44 to slide along the proection 42. Thus, and

the contact 18 is spaced from the stationary contact 14 so that thecircuit remains broken. Depression of the left-hand side of rocker 24will cause a sequence which is simply the reverse of that described sothat contact 17 is disengaged from contact 11 and thereafter contact 18is reengaged with contact 14. If desired, the recesses 33 and 43 andprojection means 32 and 42 may be designed so that the respective setsof contacts open and close at the same time.

FIG. 5 illustrates a circuit wherein the illustrated embodiment of thisinvention is of particular use. Specifically, the circuit shown is thatof a permanent magnet motor 45 which is driven by AC current receivedfrom line plug 46 through the full wave rectifying bridge 47. A switch48, corresponding to that described in connection with FIGS. l4 is shownin the ON position wherein one of the contacts, for example 18, is in aposition to complete the circuit to the rectifier bridge while the othercontact 17 is in the disconnected position. Thus, this 50 An elefmcswlich as i i m clam 1 wherem the position would correspond to thatShown in FIGS 1, 2A and length of said extending portion IS greater thanthe length of 2B the movement of said projection means in said recessedportion and wherein, during switch movement in either direction, saidprojection means engages the extending portion of the initially closedcontacts prior to disengaging the extending porstationary contact insaid second position.

3. An electric switch as claimed in claim 1 and including means biasingsaid movable contacts toward said stationary contacts. I

4. An electric switchas claimed in claim 1 wherein said extendingportion of said one movable contact is located on the opposite side ofsaid projection means from said extending portion of the remainder ofsaid movable contacts whereby movement of said movable contacts in onedirection causes opposite switching effects. 5. An electric switch asclaimed in claim 4 wherein the stationary contacts engaged by said oneand said remainder of said movable contacts are respectively located onopposite sides of said projection means.

In such motors, it is desirable that braking action be provided to stoprotation of the rotor very quickly after the power to the motor has beendisconnected. This may best be 5 achieved by providing a short circuitbetween the brushes 51 tion of the initially open contacts whereby saidinitially closed so that current in a reverse direction is provided byresidual contacts are Opened before sald y p Contacts are energy withinthe rotor and this interacts with the magnetic closedfield of thepermanent magnets 52 to stop rotation very An electric switch as claimedin claim I wherein each of quickly. However, connection of the shortcircuit via contact 6 movable comacis P" a bridge between a P of 17before the power is disconnected via contact 18 would also stahohal'ycohtacisi said extending P respectively provide a short circuit acrossthe power line. To avoid this, it is gages and disengage-5 one Contactof said P and h r necessary that the contact 18 be opened before thecontact 17 Portion Ofsaid movable Contact remains in Sliding engagementis closed. As previously described, this is accomplished by with theother Contact Ofsaid P means f the illustrated embodiment and operationf the 8. An electric switch as claimed in claim 7 wherein said exrockeror other operator-controlled means causes the contact tending Portion ofSaid one movable Contact is located n th 18 to open followed by closureof the contact 17, as illustrated pp si Side Of Said P j i n m ns fromsaid extending by the OFF position shown in dashed lines in FIG. 5.portion of the remainder of said movable contacts whereby The foregoingdescription is of an illustrative embodiment movement of said movablecontacts in one direction causes of the subject invention and it isclear that many changes and opposite switching efiects. modificationsmay be made by those skilled in the art. It is ac- 9. An electric switchas claimed in claim 8 wherein said cordingly intended that the appendedclaims cover all such means for moving said movable contacts comprises apivot, changes and modifications as may be within the true spirit androcker means mounted at said pivot, and means for converting scope ofthis invention. rotary motion of said rocker means about said pivot intolinear I claim: motion of said contacts between said positions.

said projection separates said extending portion from said saidprojection means engages the extending portion of the initially closedcontacts prior to disengaging the extending portion of the initiallyopen contacts whereby said initially closed contacts are opened beforesaid contacts are closed.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. a 934Dated AUGUST 10, 1971 O Inventods) WILLIAM H. 0 Cormon, I I

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

COLUMN 2, LINE 6, BETWEEN "SECOND" AND osnnon", msEr-rr STABLE LINE 18,"25" SHOULD BE 15 COLUMN 6, LINE 4, BETWEEN "smo" AND "CONTACTS", INSERTINITIALLY OPEN Signed and sealed this 30th day of May 1972.

(SEAL) Amer; t1:

EDWARD I LFIEECJEILER ,JR. ROBERT GOTTSCHALK Attesting OfficerCommissioner of Patents M po'wso (m'sg) uscoMM-Dc suave-Poe a I-LSGOVERNMENT PRINYING OFFICE I '9" 0-5..1!

1. A multiple pole electric switch of the type wherein different polesare respectively connected and disconnected by a single movement of theswitch comprising: an insulator base; a plurality of stationaryelectrical contacts mounted on said base; a plurality of movableelectrical contacts mounted for longitudinal movement relative to saidbase, each of said movable contacts having a portion arranged to bemoved into engagement with one of said stationary contacts; said movablecontacts and said base having cooperating camming surfaces; each of saidmovable contacts being movable between a first position wherein saidcamming surfaces permit said engaging portion to contact said stationarycontact and a second position wherein said camming surfaces separatesaid engaging portion from said stationary contact; and means for movingat least one of said movable contacts between said first and said secondpositions during the same switch operation as the movement of theremainder of said contacts between said second and said first positions.2. An electric switch as claimed in claim 1 wherein said cammingsurfaces include a projection from said base, a recessed portion in saidmovable contact, and an extending portion of said movable contact; saidengaging portion comprises a part of said extending portion; saidmovable contact being positioned so that said recessed portion registerswith said projection in said first position; and said projectionseparates said extending portIon from said stationary contact in saidsecond position.
 3. An electric switch as claimed in claim 1 andincluding means biasing said movable contacts toward said stationarycontacts.
 4. An electric switch as claimed in claim 1 wherein saidextending portion of said one movable contact is located on the oppositeside of said projection means from said extending portion of theremainder of said movable contacts whereby movement of said movablecontacts in one direction causes opposite switching effects.
 5. Anelectric switch as claimed in claim 4 wherein the stationary contactsengaged by said one and said remainder of said movable contacts arerespectively located on opposite sides of said projection means.
 6. Anelectric switch as claimed in claim 1 wherein the length of saidextending portion is greater than the length of the movement of saidprojection means in said recessed portion and wherein, during switchmovement in either direction, said projection means engages theextending portion of the initially closed contacts prior to disengagingthe extending portion of the initially open contacts whereby saidinitially closed contacts are opened before said initially open contactsare closed.
 7. An electric switch as claimed in claim 1 wherein each ofsaid movable contacts comprises a bridge between a pair of stationarycontacts, said extending portion respectively engages and disengages onecontact of said pair, and another portion of said movable contactremains in sliding engagement with the other contact of said pair.
 8. Anelectric switch as claimed in claim 7 wherein said extending portion ofsaid one movable contact is located on the opposite side of saidprojection means from said extending portion of the remainder of saidmovable contacts whereby movement of said movable contacts in onedirection causes opposite switching effects.
 9. An electric switch asclaimed in claim 8 wherein said means for moving said movable contactscomprises a pivot, rocker means mounted at said pivot, and means forconverting rotary motion of said rocker means about said pivot intolinear motion of said contacts between said positions.
 10. An electricswitch as claimed in claim 8 wherein the length of said extendingportion is greater than the length of the movement of said projectionmeans in said recessed portion and wherein, during switch movement ineither direction, said projection means engages the extending portion ofthe initially closed contacts prior to disengaging the extending portionof the initially open contacts whereby said initially closed contactsare opened before said initially open contacts are closed.